| 摘要 |
A transportable crane has its arm made in two sections (1,2) which are hinged together. The inner part consists of a braced girder with an upper beam (3') and two lower beams (6') connected by inclined struts (8). The outer part is also a braced girder but is braced alternately with rigid struts (10) and flexible tie cables (11). The struts and ties are connected by pivoted joints (14) to the upper and lower beams (3,6). When the crane is being transported the connection (22) is unbolted and upper beam is swung down between the two lower beams. The outer arm is then swung about the hinge to lie compactly along the side of the inner arm.
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